This comes from personal experience, not reading.

Your incredible questioning/self-examination is not that unusual. If you're not sure of your feelings it says less about the (potential) relationship than it does about you. And all it says about you is that you have high levels of self-consciousness, really. The longer a relationship lasts the more ending it, or having it ended on you is likely to hurt, even if you don't think you fit well together etc.

Alcohol relaxes people and makes them maudlin. As such it can be a good way to get relatively sane, sobre people to discuss their feelings together. Drinking excessively (whatever that means in context) can also get people to speak freely and give them an excuse to "not remember" the next day.

You're probably going to get over her, even if it doesn't feel like it. Any relationship or fling is likely to make the getting-over-it period shorter.

One idealises people and while I may advise you, or anyone else, I give advice. Feel free to PM me, if for some reason you'd like to.